Automotive market intelligence firm Polk reports that the average age of all light vehicles - when considering the 247 million that are registered with states' departments of motor vehicles - is approximately 11.4 years. Meanwhile, the age of light trucks is just under this total at 11.3 years.

Stretching back to 2002, the average age of both passenger cars and light trucks has risen, up from 9.8 years and 9.4 years, respectively. The trend of automobiles becoming increasingly durable is expected to continue, according to Polk experts.

Though the Southfield, Mich.-based research firm states that automobiles in general should be more long-lasting, it also forecasts with some specificity. For example, Polk projects that in five years, vehicles in operation will surpass 260 million.

How age affects auto insurance rates The age of a vehicle is something to take into consideration when reviewing auto insurance quotes. As a general rule, insurers weigh multiple different factors in determining what premiums will be for a given vehicle, including its make, model, class, as well as when the car was originally manufactured. As a general rule, the older the vehicle is, the less expensive it is to insure.

But that's not always the case. Something else insurers measure is its safety track record. For example, if a used vehicle has a history of recalls or has been involved in a number of accidents, that may affect the premiums that policyholders ultimately pay.

Additionally, some motorists may try to lengthen the life of a car far beyond what's considered appropriate or safe. However, in these instances, when a car is taken into be inspected, mechanics may give it a failing grade, preventing it from being registered and driven.

There are many different ways of determining when a car is too old to drive. This includes weakened fuel efficiency, engine problems occurring on a regular basis, rust forming along the body's exterior and failure to turn over when revving the engine. Any combination of these factors may suggest that the car should be taken off the road for good.